1. Field of the Invention
The present invention relates to a structure for the placement of a head protecting air bag body of a head protecting air bag apparatus in which, at the time when a predetermined high load is applied to a vehicle side portion, gas is ejected from an inflator such that the head protecting air bag body, which is accommodated along a roof side rail portion from a pillar portion, expands to form a curtain-like form due to the ejected gas.
2. Description of the Related Art
In order to improve the protection of the head of a vehicle occupant seated in the front seat when a predetermined high load is applied to a vehicle side portion, there have been proposed head protecting air bag apparatuses in which an air bag body, which is accommodated in a folded state along a front pillar portion and a roof side rail portion, is inflated so as to expand into a curtain-like form. The structure of such a head protecting air bag apparatus is disclosed in International Publication No. WO 96/26087, and will be described hereinafter.
As shown in FIG. 5, the head protecting air bag apparatus 100 comprises, as main components, an elongated duct 106 which is disposed so as to extend from a front pillar portion 102 along a roof side rail portion 104, an air bag body 112 which is accommodated in the duct 106 in a folded state and which is fixed to the vehicle body at a front end fixing point 108 and a rear end fixing point 110, an inflator 116 which is connected to the rear end portion of the duct 106 by a hose 114 and which ejects gas when a predetermined high load is applied to the vehicle side portion, and a strap 118 whose one end portion is fixed to the vehicle body and whose other end portion is fixed to the rear end portion of the air bag body 112. Further, the air bag body 112 is formed by connecting together a plurality of cells 120, each of which is formed in a substantially cylindrical shape whose longitudinal direction corresponds to a substantially vertical direction of the vehicle.
In accordance with the above-described structure, when a predetermined high load is applied to a vehicle side portion, gas is ejected from the inflator 116. The ejected gas flows into each of the cells 120 of the folded air bag body 112 via the hose 114 and the duct 106. As a result, each of the cells 120 is inflated so as to form a substantially cylindrical shape whose longitudinal direction substantially corresponds to the vertical direction of the vehicle. Accordingly, the air bag body 112 is inflated to form a curtain-like form along a window glass 122. Further, because the rear end portion of the air bag body 112 is connected to the vehicle body by the strap 118, the rear end portion of the air bag body 112 is reliably disposed at the inner side of the upper portion of a center pillar 124.
However, in this head protecting air bag apparatus 100, because the air bag body 112 is disposed so as to span between the front pillar portion 102 and the roof side rail portion 104, the air bag body 112 is covered with, for example, a front pillar garnish and a roof head lining. As a result, at the time of expansion of the air bag body, portions adjacent to the edge portions of the front pillar garnish and the roof head lining are deformed, and the air bag body expands forwards the vehicle interior from the deformed portions. Further, an opening trim is fitted into a vehicle door opening portion for the purpose of protecting the respective edge portions of the front pillar panel, the roof side rail panel, and the like. For this reason, at the time of expansion of the air bag body, the air bag body directly contacts the mounting portion of the opening trim which is fitted into the vehicle door opening portion, and a large amount of force is applied to the mounting portion of the opening trim. As a result, the mounting portion of the opening trim is made to deform as if opening, or the like, and the opening trim may come away from the vehicle door opening portion.